The Point-to-Point Protocol utility (PPPD) initiates and manages
a Point-to-Point Protocol (PPP) network connection and its link
parameters from an OpenVMS Alpha host system.
For information about the PPP driver and its programming
interface, see the files PPP_INTERFACES.TXT and PPP_INTERFACES.PS
in SYS$SYSROOT:[SYSHLP.EXAMPLES.PPPD.DOC].
1 – Usage Summary
The Point-to-Point Protocol utility (PPPD) allows you to initiate
and control a Point-to-Point Protocol (PPP)-compliant network
connection from an OpenVMS Alpha host and define its physical
link parameters.
Specifically, you can use this utility to:
o Create an asynchronous (ASN) device. PPPD creates the device
automatically if one is not currently associated with a serial
port (such as TTA1).
o Set both PPP and ASN device characteristics such as flow
control and baud rate.
o Inform the network stacks that there is a new physical
transport that uses the PPP.
o Act as a simple terminal emulator when establishing a
connection to a new system (asynchronous only).
o Display configuration information about the ASN and PPP device
drivers as well as any ongoing PPPD sessions.
Format
$ PPPD
The utility then displays the following prompt:
PPPD>
After invoking PPPD, you can perform PPPD operations by entering
the appropriate commands. You can also enter a single PPPD
command on the same line as the command that invokes the utility,
for example:
$ PPPD CONNECT TTAO:
To exit from the Point-to-Point Protocol utility, enter the
EXIT command at the PPPD> prompt or press Ctrl/Z. Either method
returns control to the DCL command level.
For information about the PPPD utility, enter the HELP command at
the PPPD> prompt.
2 – Commands
The following topics describe and provide examples of the PPPD
commands. If you need to customize your PPP settings, command
qualifiers are provided. However, most users will be satisfied
with the default settings. PPPD Command Summary summarizes the PPPD
command functions.
Table 1 PPPD Command Summary
Command Function
CONNECT Establishes a network connection through the
current physical port or a specified remote port.
DIAL_OUT Allows direct access to a device to dial out over
a modem or link to an external device.
DISCONNECT Terminates the network connection and returns
control to the terminal driver.
EXIT Leaves the utility and returns you to the DCL
command prompt ($).
HELP Displays help text for PPPD commands.
SET Determines the device and line characteristics for
the specified terminal.
SHOW Displays the device and line characteristics of
the specified terminal.
3 – CONNECT
Establishes a network connection to a device located on the
current physical port or specified remote port.
Format
CONNECT device-name[:]
3.1 – Parameter
device-name[:]
Optional. Supplies the name of a device through which the network
connection is made. The device name has the form ddcu where dd
is the device code, c is the controller designation, and u is the
unit number. LAN devices are specified as the name of the device
that is unit 0. For example, the first terminal device on a LAN
is specified as TTA0, the second as TTB0.
3.2 – Qualifiers
None.
3.3 – Example
PPPD> CONNECT TTA1:
%PPPD-I-CONNECTTERM, converting connection on device _TTA1: to a
Point-to-Point connection
The command in this example creates a temporary network
connection to the serial port TTA1. The port is ready to
receive the PPP setup negotiations initiated by the host at
the other end of the serial connection.
4 – DIAL_OUT
Provides access to a specific physical device to dial a modem or
link to an external device.
Format
DIAL_OUT device-name[:]
4.1 – Parameter
device-name[:]
Supplies the name of a device over which the network connection
is made. The device name has the form ddcu where dd is the device
code, c is the controller designation, and u is the unit number.
LAN devices are specified as the name of the device that is unit
0. For example, the first terminal device on a LAN is specified
as TTA0, the second as TTB0.
4.2 – Qualifiers
4.2.1 /BREAK
/BREAK=break-character
Specifies a character sequence that you can use to interrupt the
signal being currently transmitted. To interrupt the signal, type
Ctrl/break-character. You can select any ASCII character from @
though Z, except C, M, Q, S, and Y. The default break character
is ~.
4.2.2 /DISCONNECT
/DISCONNECT=disconnect-character
Specifies a character sequence that you can use to terminate
DIAL_OUT mode. To disconnect the call, type Ctrl/disconnect-
character. You can select any ASCII character from @ though Z,
except C, M, Q, S, and Y. The default disconnect character is \.
4.2.3 /SWITCH
/SWITCH=switch-character
Specifies a character sequence that you can use to switch the
line to PPP mode. To activate PPP mode, type Ctrl/switch-
character. You can select any ASCII character from @ though Z,
except C, M, Q, S, and Y. The default switch character is @.
Similar to the CONNECT command, this qualifier switches a
line into PPP mode. If the packet negotiations fail, PPPD
exits and the line is left in terminal mode. If line is set to
/MODEM and /NOHANGUP, this can result in extraneous data, the
ASCII representation of Internet Protocol (IP) packets, being
transmitted across the open line.
5 – DISCONNECT
Terminates the current network connection.
Format
DISCONNECT device-name[:]
5.1 – Parameter
device-name[:]
Optional. Indicates the name of a device over which the network
connection occurred. The device name has the form ddcu where dd
is the device code, c is the controller designation, and u is the
unit number. LAN devices are specified as the name of the device
that is unit 0. For example, the first terminal device on a LAN
is specified as TTA0, the second as TTB0.
5.2 – Qualifiers
None.
PPPD> DISCONNECT TTA1:
The command in this example terminates the current network
connection established through the serial port TTA1.
NOTE
A user must have the same UIC as the one on the ASNn: device
for the connection, or have SYSPRV privilege to disconnect a
serial port.
6 – EXIT
Stops the execution of PPPD and returns control to the DCL
command level. You can only enter Ctrl/Z if the line has not
already been switched to PPP mode.
Format
EXIT
6.1 – Parameters
None.
6.2 – Qualifiers
None.
PPPD> EXIT
The command in this example leaves the PPPD utility and returns
control to the DCL command level.
7 – HELP
Provides online help information for using the PPPD commands.
Format
HELP [command-name...]
7.1 – Parameter
command-name
The name of a PPPD command or PPPD command and command keyword.
If you enter the HELP command with a command name only, such as
HELP SET, PPPD displays a list of all of the command keywords
used with the SET command.
PPPD> HELP DISCONNECT
In this example, the HELP DISCONNECT command produces a
description of the DISCONNECT command and shows the command
format.
8 – SET
Sets the communication line characteristics for a specific
terminal device.
Format
SET device-name[:]
8.1 – Parameter
device-name
Indicates the name of the device whose characteristics are to
be set. The device name has the form ddcu where dd is the device
code, c is the controller designation, and u is the unit number.
LAN devices are specified as the name of the device that is unit
0. For example, the first terminal device on a LAN is specified
as TTA0, the second as TTB0.
8.2 – Qualifiers
8.2.1 /ADDRESS_COMPRESSION
/ADDRESS_COMPRESSION (default)
/NOADDRESS_COMPRESSION
Indicates whether the address and control fields are compressed.
8.2.2 /CLEAR_COUNTERS
/CLEAR_COUNTERS=(keyword,...)
Determines which counters to clear when trying to resolve
performance problems. The default is to clear all counters. With
this qualifier, you can specify one or more of the following
keywords:
Keyword Description
ALL Resets all counters.
BAD_FCS_PACKETS Resets the count of packets with a bad frame
check sequence (FCS).
DATA_LOST Resets the count of lost characters that were
reported by hardware.
DROPPED_ Resets the count of all characters thrown away.
CHARACTERS
FRAMING_ERRORS Resets the count of characters with framing
errors.
LONG_PACKETS Resets the count of packets longer than the
current maximum receive unit (MRU) setting.
RECEIVED_ Resets the count of total packets received.
PACKETS
RUNT_PACKETS Resets the count of packets with too few
characters.
TOTAL_ Resets the count of all characters received.
CHARACTERS
TRANSMITTED_ Resets the count of total packets transmitted.
PACKETS
8.2.3 /CONNECT
Sets the line parameters and binds the ASN device to the physical
terminal.
8.2.4 /ECHO
/ECHO=(FAILURE=value, INTERVAL=value)
Specifies the number of Link Control Protocol (LCP) echo requests
and the interval between requests that must be sent without
response before the line is considered down. The default number
of echo requests is 0.
8.2.5 /FLOW_CONTROL
/FLOW_CONTROL=control-option
Indicates the type of flow control used over the physical
link. You can specify one of the following keywords with this
qualifier:
Keyword Description
HARDWARE Uses RTS/CTS flow control. If using this control, the
transmit Asynch Control Character Map (ACCM) can be
0x0, 0x0, 0x0, 0x60000000. Only valid for lines set to
/MODEM or /COMMSYNCH.
XON_XOFF Uses band flow control. If using this control, the
(de- optimal transmit ACCM is 0xA0000, 0x0, 0x0, 0x60000000.
fault) Only valid for asynchronous lines.
8.2.6 /HANGUP
/HANGUP
/NOHANGUP
Determines the action that occurs when a session is terminated.
This qualifier notifies the ASN driver when a modem hangup is
necessary due to an idle device. For example, when the last
network connection is closed on a transient line that is set
to /NOHANGUP, the line switches back to the terminal driver but
the modem remains connected. This allows users to reaccess the
line and log in without having to redial and reestablish the
connection.
To use this qualifier, you must have PHY_IO privilege, or the
line must have TT2$M_MODHANGUP already set.
8.2.7 /MAGIC_NUMBER_RETRIES
/MAGIC_NUMBER_RETRIES=value
Specifies the number of attempts made to negotiate a magic
number. Magic numbers are used to detect looped back connections.
If you specify 0, no negotiations are made. If you specify 255,
negotiation continues until a number is found. The default number
of attempts is 5.
8.2.8 /MAXCONFIGURE
/MAXCONFIGURE=value
Indicates the number of configure-request packets sent without
receiving a valid configure-ack, configure-nak, or configure-
reject before assuming the peer is unable to respond. Specify
a value in the range of 0 to 255. The default number of packets
sent is 10.
8.2.9 /MAXFAILURE
/MAXFAILURE=value
Indicates the number of configure-nak packets sent without
receiving a valid configure-ack before assuming that the
configuration is not converging. Specify a value in the range
of 0 to 255. The default number of packets sent is 5.
8.2.10 /MAXTERMINATE
/MAXTERMINATE=value
Indicates the number of terminate-request packets sent without
receiving a terminate-ack before assuming that the peer is unable
to respond. Specify a value in the range of 0 to 255. The default
number of packets is 2.
8.2.11 /MRU
/MRU=size
Specifies the largest packet that can be received over the line.
This value is used as part of the line negotiation, and the
actual MRU setting can vary. Specify a value in the range of 6
to 1500. The default packet size is 1500.
8.2.12 /MTU
/MTU=size
Specifies the largest packet that can be transmitted over the
line. This value is used as part of the line negotiation, and the
actual maximum transfer unit (MTU) setting can vary. Specify a
value in the range of 6 to 1500. The default packet size is 1500.
8.2.13 /NETWORK_PROTOCOL
/NETWORK_PROTOCOL=(protocol-name)
Specifies the the protocol allowed over the link. The default
network protocol is TCP/IP.
8.2.14 /PASSIVE
/PASSIVE
/NOPASSIVE (default)
Notifies the PPP driver how to handle the PPP connection. It can
either actively initiate the connection or wait for the remote
host to start the connection.
8.2.15 /PERMANENT
/PERMANENT
/NOPERMANENT
Determines how the link is handled when a connection is closed or
lost. If you specify /PERMANENT, the link remains in place with
the PPP driver in control. If you specify /NOPERMANENT, the link
is treated as a transient connection, and the terminal reverts to
the terminal driver.
8.2.16 /PROTOCOL_COMPRESSION
/PROTOCOL_COMPRESSION (default)
/NOPROTOCOL_COMPRESSION
Specifies whether the two octet protocol fields are compressed
into a single octet.
8.2.17 /RECEIVE_ACCM
/RECEIVE_ACCM=mask-value
Identifies the starting Asynch Control Character Map (ACCM).
This mask is used by the PPP driver to negotiate the final ACCM
for asynchronous ports. Specify a mask in the range of 0x0 to
0xFFFFFFFF. The default mask value is 0xFFFFFFFF, 0x0, 0x0,
0x60000000, 0x0, 0x0, 0x0. The masks are ordered from low-order
longword to high-order longword. Specify the longword mask until
the last mask bits are set. The remaining longwords are set to
0. With 8 longwords, there is 1 bit for every ASCII character
position (from 0 to 255). The ASCII characters 0x20 through 0x3F
and 0x5E cannot be quoted.
8.2.18 /RESTART_TIMER
/RESTART_TIMER=msecs
Interval in milliseconds (msecs) used to time the transmission
of configure-request and terminate-request packets. Expiration of
the restart timer results in a timeout event and retransmission
of the packet. Specify a value from 1 to 90. The default is 30
(.03 seconds), which is intended for relatively slow speed links.
For smaller, faster links, specify a smaller value.
8.2.19 /SPEED
/SPEED=(input-rate,output-rate)
Allows you to control the input and output speed of the line for
asynchronous ports. To use this qualifier, you must have PHY_IO
privilege, or the line must already have TT2$M_SETSPEED set.
Specify one of the following speeds: 50, 75, 100, 134, 150, 300,
600, 1200, 1800, 2400, 3600, 4800, 7200, 9600, 19200, 38400,
57600, 76800, or 115200. If your line allows split speed, you
can specify different speeds for input and output. If you only
specify one speed, it is used for both input and output.
8.2.20 /TRANSMIT_ACCM
/TRANSMIT_ACCM=mask-value,...
Identifies the starting Asynch Control Character Map (ACCM). This
mask is used by the PPP driver to negotiate the final transmit
ACCM for asynchronous ports. Specify a mask in the range of 0x0
to 0xFFFFFFFF. The default mask value is 0xFFFFFFFF, 0x0, 0x0,
0x60000000, 0x0, 0x0, 0x0. The masks are ordered from low-order
longword to high-order longword. Specify the longword mask until
the last mask bits are set. The remaining longwords are set to
0. With 8 longwords, there is 1 bit for every ASCII character
position (from 0 to 255). The ASCII characters 0x20 through 0x3F
and 0x5E cannot be quoted.
PPPD> SET/PERMANENT TTA0:
%PPPD-I-CONNECTTERM, converting connection on device _TTA0: to a
Point-to-Point connection
In this example, the SET command is setting up a permanent
network connection over the serial port TTA0.
9 – SHOW
Allows you to display the communication characteristics for a
specific terminal.
Format
SHOW device-name[:]
9.1 – Parameter
device-name[:]
Supplies the name of the device whose characteristics are to
be displayed. The device name has the form ddcu where dd is the
device code, c is the controller designation, and u is the unit
number. LAN devices are specified as the name of the device that
is unit 0. For example, the first terminal device on a LAN is
specified as TTA0, the second as TTB0.
9.2 – Qualifiers
9.2.1 /ADDRESS_COMPRESSION
Indicates whether the address compression is on or off.
9.2.2 /ALL
/ALL[=BRIEF] (default)
/ALL[=LONG]
Displays all the current device and communication settings. BRIEF
formats the output for the screen. LONG displays each setting on
a separate line.
9.2.3 /COUNTERS
/COUNTERS=(keyword,...)
Shows the current values for the specified counter(s). You
can specify one or more of the following keywords with this
qualifier:
Keyword Description
ALL Displays all counters.
BAD_FCS_PACKETS Displays the count of packets with bad frame
check sequence (FCS).
DATA_LOST Displays the count of lost characters that were
reported by hardware.
DROPPED_ Displays the count of all characters thrown
CHARACTERS away.
FRAMING_ERRORS Displays the count of characters with framing
errors.
LONG_PACKETS Displays the count of packets longer than the
current maximum receive unit setting (MRU).
RECEIVED_ Displays the count of total packets received.
PACKETS
RUNT_PACKETS Displays the count of packets with too few
characters.
TOTAL_ Displays the count of all characters received.
CHARACTERS
TRANSMITTED_ Displays the count of total packets transmitted.
PACKETS
9.2.4 /ECHO
/ECHO=(FAILURE=value, INTERVAL=value)
Specifies the number of Link Control Protocol (LCP) echo requests
and the interval (in milliseconds) between requests that must be
sent without response before the line is considered down.
9.2.5 /FCS_SIZE
Shows the current receive and transmit FCS size in bits.
9.2.6 /FLOW_CONTROL
/FLOW_CONTROL=(keyword,...)
Shows the current flow control setting used over the asynchronous
physical link. You can specify one of the following keywords with
this qualifier:
Keyword Description
HARDWARE Uses RTS/CTS flow control. If using this control, the
transmit Asynch Control Character Map (ACCM) can be
0x0, 0x0, 0x0, 0x60000000. Only valid for lines set to
/MODEM or /COMMSYNCH.
XON_XOFF Uses band flow control. If using this control, the
(de- optimal transmit ACCM is 0xA0000, 0x0, 0x0, 0x60000000.
fault) Only valid for asynchronous lines.
9.2.7 /HANGUP
Displays the action that occurs when a session is terminated.
9.2.8 /MAGIC_NUMBER_RETRIES
Shows the number of attempts that are made to negotiate a magic
number.
9.2.9 /MAXCONFIGURE
Shows the number of configure-request packets sent without
acknowledgment before assuming that the peer is not responding.
9.2.10 /MAXFAILURE
Displays the number of configure-nak packets sent before sending
a configure-ack and before assuming that the configuration is not
converging.
9.2.11 /MAXTERMINATE
Shows the number of terminate-request packets sent without
acknowledgment before assuming the peer is unable to respond.
9.2.12 /MRU
Displays the largest packet that the line can receive.
9.2.13 /MTU
Displays the largest packet that the line can transmit.
9.2.14 /NETWORK_PROTOCOL
Displays the current network protocol(s) allowed over the
physical link.
9.2.15 /PASSIVE
Indicates whether this is a passive or active line.
9.2.16 /PERMANENT
Indicates whether this is a permanent or transient (nonpermanent)
line.
9.2.17 /PROTOCOL_COMPRESSION
Shows the status of protocol field compression.
9.2.18 /RECEIVE_ACCM
Displays the value of the current receive ACCM for asynchronous
ports.
9.2.19 /RESTART_TIMER
Displays the interval used to time transmission of request
packets.
9.2.20 /SPEED
Indicates the current input and output speeds of the line.
9.2.21 /TRANSMIT_ACCM
Displays the value of the current transmit ACCM for asynchronous
ports.